SIGNS OF PREGNANCY 299
The Xenopus test9 or Hogl>en test may be used when a rapid diagnosis
of early pregnancy is to be made. One c.cm. of prepared urine from the
suspected case is injected into the lymph sac of a South African female toad
(Xenopus Isevis), and extrusion of ova through the cloaca occurs within
six to fifteen hours, if pregnancy is present.
Male frogs and toads may be employed instead of female toads. One
millilitre of the filtered first morning urine of the suspected case of preg-
nancy is injected into the dorsal lymph sacs of two male toads. One to four
hours later cloaca! samples of urine are withdrawn from both the toads by
catheterization, and examined under the low power of a microscope.
Spermatozoa in large numbers will be found floating on the glass slide, if
pregnancy is present. It is advisable to collect the toads' urine at the time
of injection and to check the absence of spermatozoa. Moha&ty and
Pabrai10 recommend the injection of 10 millilitres of the patient's untreated
urine into the dorsal lymph sacs of three healthy male toads (Bufo Melano-
stictus Schneid), weighing from 50 to 70 grammes. A positive reaction is
seen by the presence of spermatozoa in the toads' samples of urine after half
to four hours. This test is simple, inexpensive, rapid and highly accurate.
The same toads can be utilized every ten to twelve days with proper feeding.
Signs of Pregnancy in the Dead.—In addition to some of the objective
signs mentioned above, the diagnostic signs of pregnancy which are found
in the dead body at the post-mortem examination are—
1. The presence of an ovum or foetus.
2. Uterine changes.
3. The corpus luteum.
1. The Presence of an Ovum or Foetus.—The presence of an impreg-
nated ovum, foetus or placenta in the uterus after death is positive proof of
pregnancy. In place of the ovum certain abnormal products of conception,
such as sanguineous and vesicular moles, may sometimes be present. These
moles develop so rapidly that the uterus is usually larger than at the
corresponding period of normal pregnancy, but more frequently it is not
enlarged beyond its size at the fifth or sixth month of gestation.
2. Uterine Changes.—As a result of pregnancy the uterus is thickened,
and increases in size, both in its length and width. The length increases
from one and-a-half inches to twelve inches, and the width from one and-
a-half to about nine inches. Its weight at the full term of pregnancy is
twenty-eight ounces or more.
The nulliparous uterus weighs about an ounce, and that of the woman
who has borne children weighs about an ounce and a half. The uterus also
increases very much in its capacity, being five hundred or more cubic inches
at its full development. The marks of the attachment of the placenta are
3. The Corpus Luteum.—The corpus luteum is a cicatrix formed in the
ovary after the escape of ova from the bursting of a Graafian follicle at the
menstrual period. This corpus luteum develops in size for the first five or
six days after the rupture of the follicle, remains quiescent for a few days
more and then undergoes rapid absorption. In the event of pregnancy the
corpus luteum continues to develop, and attains the largest size about the
fourth month, forming a firm projection on the surface of the ovary. It ti^e^
undergoes a slow retrogressive change, although it is usually well mi^Slfe
at the time of delivery, and may be evident for one or two months
1 r" v&'K-!^, 'M
9. Edward R. Elkan, Brit Med. Jour., Dec. 17, 1928, p. 1,253; F.
Med. Journ April 15, 1939, p. 766.
10. Ind. Med. Gaz., Feb. 1950, p. 43.